Izabela Janowska - Academia.edu (original) (raw)

Open Access by Izabela Janowska

Few layer graphene (FLG) was synthesized by μ -wave assisted exfoliation of expanded graphite in ... more Few layer graphene (FLG) was synthesized by μ -wave assisted exfoliation of expanded graphite in toluene with an overall yield from c.a. 7% to 20%. A significant difference in the absorption of μ -waves by the expanded graphite and toluene allowed a rapid heating of the medium. The number of FLG sheets varies from 3 to 12, while the lateral size of the sheets exceeds few μ ms. The obtained FLG exhibits very low resistance with average value of 1.6 k Ω (500 Ω minimum) which is comparable to that of high quality graphenes synthesized by CVD methods, and lower than numbers of exfoliated graphenes.

Papers by Izabela Janowska

ChemEngineering, Oct 8, 2022

This article is an open access article distributed under the terms and conditions of the Creative... more This article is an open access article distributed under the terms and conditions of the Creative Commons Attribution (CC BY

Near-phase-pure nanoparticle iron carbides (Fe3C and Fe5C2) were synthesised. Debye model calcula... more Near-phase-pure nanoparticle iron carbides (Fe3C and Fe5C2) were synthesised. Debye model calculations were used with hyperfine parameters gathered by 57 Fe Mössbauer spectroscopy within a temperature range of 10 K to 293 K, with analysis providing Debye temperatures of 422 K and 364 K for two Fe sites in Fe5C2 and 355 K for ferromagnetic Fe3C. The intrinsic isomer shifts were calculated as 0.45 mm s −1 and 0.43 mm s −1 for iron sites 1 and 2 respectively in Fe5C2 and 0.42 mm s −1 for Fe3C. Recoil-free fractions for the two iron sites were also calculated at f300 0.785 and 0.726 for site 1 and 2 respectively.

Surfaces and Interfaces, Feb 1, 2023

Materials Science And Engineering: B, May 1, 2018

In the present investigation, we point out the effect of the substrate crystallinity on the growt... more In the present investigation, we point out the effect of the substrate crystallinity on the growth rate, efficiency, quality and the structure of synthesized aligned carbon nanotubes (CNTs). Three substrates are tested: amorphous alumina (Al 2 O 3), silica (Si/SiO 2), and crystalline alumina (sapphire). The growth is carried out using the floating catalyst-CVD process with the ferrocene-toluene solution as precursor. In addition, different concentrations of H 2 in the gas supply are investigated. It is observed that the sapphire substrate provides a more homogenous forest of vertically oriented straight nanotubes with small diameter, despite initial horizontal alignment of the nanotubes. In the presence of H 2 , long arrays of high L/Φ aspect ratio nanotubes were obtained with a reduction of diameter and the number of walls. L/Φ aspect ratio in the case of 7% H 2 is c.a. 3600 for sapphire substrate, 1500 and 2000 for alumina and silica amorphous substrate, respectively. When sapphire substrate is used, the increase of H 2 to 15% provides the L/Φ aspect ratio of ∼14,000.

Small, Dec 4, 2009

The nucleation and growth of single-walled carbon nanotubes is observed in situ in a transmission... more The nucleation and growth of single-walled carbon nanotubes is observed in situ in a transmission electron microscope. Carbon atoms are implanted into catalytically active metal particles by electron-beam sputtering. The metal particles are then shaped with a focused electron beam. Once the particles have a region of high surface curvature, spontaneous nucleation and growth of single-walled carbon nanotubes occurs on the metal particles. It is shown that the local solubility of carbon in the metal determines the nucleation of nanotubes. This is confirmed by atomistic computer simulations treating the solubility of carbon in a metal particle as a function of the size of the system.

Physical Chemistry Chemical Physics, 2015

Transcription of nanoproperties to others dimensions in efficient and simple way by appropriate d... more Transcription of nanoproperties to others dimensions in efficient and simple way by appropriate design of devices is a challenge; and conductive nanocarbon systems are concerned. Here, the evaporation induced self-assembling method is proposed to form branched, fractal-like "2D" conductive macrostructures from (nano) micro-few layer graphene flakes. The self-assembled conductive graphene networks reveal a reduction of percolation threshold compared to random arrangement (reduction of matter for a given surface and conduction at lower surface coverage), and becomes a promising matrix for conductive (transparent) films. Construction of high performance macro(micro) devices in a way that preserve the features

DESALINATION AND WATER TREATMENT, 2017

This investigation presents the advantages and limitations of tartrazine azo dye sorption on oxyg... more This investigation presents the advantages and limitations of tartrazine azo dye sorption on oxygen functionalized multiwalled carbon nanotubes (O-MWCNTs) synthesized by catalytic-CVD technique in LEREC laboratory, Algeria. Our adsorbent was characterized by FESEM, HR-TEM micrographs, Raman spectroscopy, ATG, XPS and specific surface area measurements (S BET). The effects of different operational parameters like contact time, initial concentration of tartrazine, adsorbent amount, pH and temperature on the sorption processes were studied in batch mode. Experiments showed that the O-MWCNT was efficient for the removal of tartrazine and the equilibrium can be reached in 60 min. The removal efficiency was found to be dependent on the initial dye concentration and there is no significant effect of temperature on the adsorption process. Also, acidic pH was found to be favorable for dye removal, while the adsorption capacity decreases with the O-MWCNTs amount. For comparison, a similar study has been performed with a commercial activated carbon (CAC) and it was found out that the functionalized MWCNT has a shorter equilibrium time and higher dye adsorption capacity than CAC, so that O-MWCNTs can be considered as potential adsorbents for dye removal from wastewater. The models of Langmuir and Freundlich isotherms are applicable to describe the process of tartrazine adsorption on the O-MWCNTs and also on the CAC conventional adsorbent.

ACS Sustainable Chemistry & Engineering, Mar 1, 2021

Here is presented the elaboration of Few Layer Graphene/TiO 2 photocatalytic composites (FLG/TiO ... more Here is presented the elaboration of Few Layer Graphene/TiO 2 photocatalytic composites (FLG/TiO 2) with FLG loadings from 0.5 to 11 wt.%. Contrary to commonly used (reduced) graphene oxide obtained by long and harsh conditions synthesis, FLG was synthesized by simple, fast, efficient and eco-friendly exfoliation method. The enhancement of defective/functionalized sites density for attachment of TiO 2 species was achieved via calcination process at 450 °C. The nanocomposites were evaluated toward H 2 production from methanol under artificial solar light irradiation, without the use of a co-catalyst. It was observed that the best activities are provided by the composites with the lowest loading: 0.5 and 1.0 wt.% FLG/TiO 2 that are 2-3 times more efficient than reference and commercial TiO 2. The photocatalytic activity of the composites was correlated to their surface area, morphological, structural, optical properties and kinetics of free electron mobility properties. The enhanced activity is attributed to higher surface area, better photogenerated charges separation thanks to electrons' delocalization and trapping onto graphene layers well interfaced with TiO 2 nanoparticles, but also to additional FLG visible light absorption properties and charge carriers' generation. The impact of enhanced FLG edges defects/functionalities is reflected as well via selected analysis and hydrogen generation.

Journal of Physical Chemistry C, Sep 19, 2013

The reducibility of iron oxide nanoparticles (NPs) supported over few-layer thick graphite upon a... more The reducibility of iron oxide nanoparticles (NPs) supported over few-layer thick graphite upon annealing in hydrogen is investigated by near ambient pressure X-ray photoelectron spectroscopy (NAP-XPS), X-ray absorption spectroscopy (XAS), electron energy loss spectroscopy (EELS), and high-resolution transmission electron microscopy (HR-TEM). It is found that the stability of the iron oxide NPs toward reduction is enhanced by the interaction with the graphene nanosheets as compared to the bulk iron oxide. Postannealing TEM micrographs reveal the existence of both core/shell and homogeneous iron oxide NPs with the latter forming irregular trenches into the graphene sheets. EELS analysis and TEM images clearly demonstrate that the reducibility of iron oxide particles depends on the specific graphene site on which they are attached. Furthermore, we show that graphene etching can be mediated by iron oxide NPs at relatively mild reduction conditions.

Catalysis Today, Mar 1, 2018

Carbon nanotube (CNT) supported catalysts containing ceria-zirconia mixed oxide (CeZrO 2) and nic... more Carbon nanotube (CNT) supported catalysts containing ceria-zirconia mixed oxide (CeZrO 2) and nickel were synthesized and tested in water gas shift (WGS) reaction. Physicochemical characterization including N 2 adsorption, X-ray diffraction (XRD), scanning and transmission microscopy (SEM/TEM), X-ray photoelectron spectroscopy (XPS), thermogravimetric analysis (TGA) and temperature programmed reduction with H 2 (H 2-TPR), as well as catalytic tests of WGS reaction showed that the synthesis method had significant impact on composition, morphology, structural properties and catalytic performance of obtained hybrid materials. The catalysts obtained by co-precipitation of metal oxides (NiO and/or CeZrO 2) on CNT walls demonstrated better dispersion of active phase and smaller particle size than catalyst obtained by depositing of powder CeZrO 2 or Ni-CeZrO 2. Moreover, the catalyst obtained by co-precipitation revealed better performance in WGS reaction; however, some CH 4 formation was noticed over Ni-CeZrO 2 /CNT system. The role of CeZrO 2 in catalysts performance in WGS as well as the importance of good metal-oxide contact were confirmed.

ACS omega, Dec 4, 2017

The successful future of 2D materials, which are crucial for accelerating technology development ... more The successful future of 2D materials, which are crucial for accelerating technology development and societal requirements, depends on their efficient preparation in an economical and ecological way. Herein, we present a significant advance in the top-down exfoliation and dispersion method via an aqua colloid approach. We demonstrate that a broad family of natural oil-in-water emulsification agents with an elevated hydrophilic/lipophilic balance acts in the exfoliation of layered materials and the formation of their concentrated colloids. The concentration exceeds 45 g/L for exfoliated few-layered graphene sheets possessing a micrometer size. The exfoliation of carbon nanofibers provides one of the best known unsupported and Nundoped metal-free catalysts to date in the selective dehydrogenation of ethylbenzene to styrene. Other examples include aqua colloids of exfoliated/dispersed nitrides, carbides, or nanodiamonds.

Organometallics, Aug 27, 2004

ABSTRACT The reaction of the bulky aminophenol 2-(CH2NMe2)-4-Me-6-CPh3-C6H3OH (1) with Al(iBu)3 y... more ABSTRACT The reaction of the bulky aminophenol 2-(CH2NMe2)-4-Me-6-CPh3-C6H3OH (1) with Al(iBu)3 yields via isobutane elimination the formation of the diisobutyl Al complex {6-(CH2NMe2)-2-CPh3-4-Me-C6H2O}Al(iBu)2 (2) in high yield. Reaction of 2 with B(C6F5)3 in the presence of NMe2Ph affords, along with isobutene, the salt compound [{6-(CH2NMe2)-2-CPh3-4-Me-C6H2O}Al(iBu)(NMe2Ph)][HB(C6F5)3] (3), consisting of a four-coordinate Lewis acidic Al cation associated with the borohydride HB(C6F5)3-, whose solid-state structure was determined by X-ray crystallography. When complex 2 is reacted with B(C6F5)3 (1 and 0.05 equiv) in the presence of benzophenone and benzaldehyde, the quantitative conversion to the hydroalumination products 4 and 5, respectively, is observed. This B(C6F5)3-catalyzed hydroalumination reaction, via a B(C6F5)3-mediated hydride abstraction/transfer reaction, represents a new type of reactivity for Al alkyl cations and illustrates the higher reactivity of Al cation/HB(C6F5)3- salts versus the classical Al cation/MeB(C6F5)3- and B(C6F5)4- salts.

Powder Technology, Jul 1, 2016

Journal of materials chemistry. A, Materials for energy and sustainability, 2013

Journal of materials chemistry. A, Materials for energy and sustainability, 2014

International Journal of Biological Macromolecules, Jul 1, 2023

Acta Crystallographica Section C-crystal Structure Communications, Dec 11, 2004

In the title compound, [Fe(C5H5)(C12H19NO)]I, the ferrocene moiety has an eclipsed conformation, ... more In the title compound, [Fe(C5H5)(C12H19NO)]I, the ferrocene moiety has an eclipsed conformation, with mean Fe-C bond lengths of 2.031 (4) and 2.020 (6) A for the substituted and unsubstituted cyclopentadienyl rings. The pyrrolidinium heterocycle adopts an envelope conformation and has its 1- and 2-substituents in a relative trans disposition. Strong (+/-)-charge-assisted N-H...I and C-H...I hydrogen bonds are present. The crystal structure is also stabilized by weak C-H...O interactions.

Tetrahedron-asymmetry, Oct 1, 2003

Circular dichroism spectra of a series of planar chiral 2-substituted ferrocene carboxaldehydes a... more Circular dichroism spectra of a series of planar chiral 2-substituted ferrocene carboxaldehydes and 2-ferrocenyl-1,1dicyanoethylenes are reported. They show Cotton effects associated with intramolecular charge transfer transitions and are related to the absolute configuration of these compounds.

Few layer graphene (FLG) was synthesized by μ -wave assisted exfoliation of expanded graphite in ... more Few layer graphene (FLG) was synthesized by μ -wave assisted exfoliation of expanded graphite in toluene with an overall yield from c.a. 7% to 20%. A significant difference in the absorption of μ -waves by the expanded graphite and toluene allowed a rapid heating of the medium. The number of FLG sheets varies from 3 to 12, while the lateral size of the sheets exceeds few μ ms. The obtained FLG exhibits very low resistance with average value of 1.6 k Ω (500 Ω minimum) which is comparable to that of high quality graphenes synthesized by CVD methods, and lower than numbers of exfoliated graphenes.

ChemEngineering, Oct 8, 2022

This article is an open access article distributed under the terms and conditions of the Creative... more This article is an open access article distributed under the terms and conditions of the Creative Commons Attribution (CC BY

Near-phase-pure nanoparticle iron carbides (Fe3C and Fe5C2) were synthesised. Debye model calcula... more Near-phase-pure nanoparticle iron carbides (Fe3C and Fe5C2) were synthesised. Debye model calculations were used with hyperfine parameters gathered by 57 Fe Mössbauer spectroscopy within a temperature range of 10 K to 293 K, with analysis providing Debye temperatures of 422 K and 364 K for two Fe sites in Fe5C2 and 355 K for ferromagnetic Fe3C. The intrinsic isomer shifts were calculated as 0.45 mm s −1 and 0.43 mm s −1 for iron sites 1 and 2 respectively in Fe5C2 and 0.42 mm s −1 for Fe3C. Recoil-free fractions for the two iron sites were also calculated at f300 0.785 and 0.726 for site 1 and 2 respectively.

Surfaces and Interfaces, Feb 1, 2023

Materials Science And Engineering: B, May 1, 2018

In the present investigation, we point out the effect of the substrate crystallinity on the growt... more In the present investigation, we point out the effect of the substrate crystallinity on the growth rate, efficiency, quality and the structure of synthesized aligned carbon nanotubes (CNTs). Three substrates are tested: amorphous alumina (Al 2 O 3), silica (Si/SiO 2), and crystalline alumina (sapphire). The growth is carried out using the floating catalyst-CVD process with the ferrocene-toluene solution as precursor. In addition, different concentrations of H 2 in the gas supply are investigated. It is observed that the sapphire substrate provides a more homogenous forest of vertically oriented straight nanotubes with small diameter, despite initial horizontal alignment of the nanotubes. In the presence of H 2 , long arrays of high L/Φ aspect ratio nanotubes were obtained with a reduction of diameter and the number of walls. L/Φ aspect ratio in the case of 7% H 2 is c.a. 3600 for sapphire substrate, 1500 and 2000 for alumina and silica amorphous substrate, respectively. When sapphire substrate is used, the increase of H 2 to 15% provides the L/Φ aspect ratio of ∼14,000.

Small, Dec 4, 2009

The nucleation and growth of single-walled carbon nanotubes is observed in situ in a transmission... more The nucleation and growth of single-walled carbon nanotubes is observed in situ in a transmission electron microscope. Carbon atoms are implanted into catalytically active metal particles by electron-beam sputtering. The metal particles are then shaped with a focused electron beam. Once the particles have a region of high surface curvature, spontaneous nucleation and growth of single-walled carbon nanotubes occurs on the metal particles. It is shown that the local solubility of carbon in the metal determines the nucleation of nanotubes. This is confirmed by atomistic computer simulations treating the solubility of carbon in a metal particle as a function of the size of the system.

Physical Chemistry Chemical Physics, 2015

Transcription of nanoproperties to others dimensions in efficient and simple way by appropriate d... more Transcription of nanoproperties to others dimensions in efficient and simple way by appropriate design of devices is a challenge; and conductive nanocarbon systems are concerned. Here, the evaporation induced self-assembling method is proposed to form branched, fractal-like "2D" conductive macrostructures from (nano) micro-few layer graphene flakes. The self-assembled conductive graphene networks reveal a reduction of percolation threshold compared to random arrangement (reduction of matter for a given surface and conduction at lower surface coverage), and becomes a promising matrix for conductive (transparent) films. Construction of high performance macro(micro) devices in a way that preserve the features

DESALINATION AND WATER TREATMENT, 2017

This investigation presents the advantages and limitations of tartrazine azo dye sorption on oxyg... more This investigation presents the advantages and limitations of tartrazine azo dye sorption on oxygen functionalized multiwalled carbon nanotubes (O-MWCNTs) synthesized by catalytic-CVD technique in LEREC laboratory, Algeria. Our adsorbent was characterized by FESEM, HR-TEM micrographs, Raman spectroscopy, ATG, XPS and specific surface area measurements (S BET). The effects of different operational parameters like contact time, initial concentration of tartrazine, adsorbent amount, pH and temperature on the sorption processes were studied in batch mode. Experiments showed that the O-MWCNT was efficient for the removal of tartrazine and the equilibrium can be reached in 60 min. The removal efficiency was found to be dependent on the initial dye concentration and there is no significant effect of temperature on the adsorption process. Also, acidic pH was found to be favorable for dye removal, while the adsorption capacity decreases with the O-MWCNTs amount. For comparison, a similar study has been performed with a commercial activated carbon (CAC) and it was found out that the functionalized MWCNT has a shorter equilibrium time and higher dye adsorption capacity than CAC, so that O-MWCNTs can be considered as potential adsorbents for dye removal from wastewater. The models of Langmuir and Freundlich isotherms are applicable to describe the process of tartrazine adsorption on the O-MWCNTs and also on the CAC conventional adsorbent.

ACS Sustainable Chemistry & Engineering, Mar 1, 2021

Here is presented the elaboration of Few Layer Graphene/TiO 2 photocatalytic composites (FLG/TiO ... more Here is presented the elaboration of Few Layer Graphene/TiO 2 photocatalytic composites (FLG/TiO 2) with FLG loadings from 0.5 to 11 wt.%. Contrary to commonly used (reduced) graphene oxide obtained by long and harsh conditions synthesis, FLG was synthesized by simple, fast, efficient and eco-friendly exfoliation method. The enhancement of defective/functionalized sites density for attachment of TiO 2 species was achieved via calcination process at 450 °C. The nanocomposites were evaluated toward H 2 production from methanol under artificial solar light irradiation, without the use of a co-catalyst. It was observed that the best activities are provided by the composites with the lowest loading: 0.5 and 1.0 wt.% FLG/TiO 2 that are 2-3 times more efficient than reference and commercial TiO 2. The photocatalytic activity of the composites was correlated to their surface area, morphological, structural, optical properties and kinetics of free electron mobility properties. The enhanced activity is attributed to higher surface area, better photogenerated charges separation thanks to electrons' delocalization and trapping onto graphene layers well interfaced with TiO 2 nanoparticles, but also to additional FLG visible light absorption properties and charge carriers' generation. The impact of enhanced FLG edges defects/functionalities is reflected as well via selected analysis and hydrogen generation.

Journal of Physical Chemistry C, Sep 19, 2013

The reducibility of iron oxide nanoparticles (NPs) supported over few-layer thick graphite upon a... more The reducibility of iron oxide nanoparticles (NPs) supported over few-layer thick graphite upon annealing in hydrogen is investigated by near ambient pressure X-ray photoelectron spectroscopy (NAP-XPS), X-ray absorption spectroscopy (XAS), electron energy loss spectroscopy (EELS), and high-resolution transmission electron microscopy (HR-TEM). It is found that the stability of the iron oxide NPs toward reduction is enhanced by the interaction with the graphene nanosheets as compared to the bulk iron oxide. Postannealing TEM micrographs reveal the existence of both core/shell and homogeneous iron oxide NPs with the latter forming irregular trenches into the graphene sheets. EELS analysis and TEM images clearly demonstrate that the reducibility of iron oxide particles depends on the specific graphene site on which they are attached. Furthermore, we show that graphene etching can be mediated by iron oxide NPs at relatively mild reduction conditions.

Catalysis Today, Mar 1, 2018

Carbon nanotube (CNT) supported catalysts containing ceria-zirconia mixed oxide (CeZrO 2) and nic... more Carbon nanotube (CNT) supported catalysts containing ceria-zirconia mixed oxide (CeZrO 2) and nickel were synthesized and tested in water gas shift (WGS) reaction. Physicochemical characterization including N 2 adsorption, X-ray diffraction (XRD), scanning and transmission microscopy (SEM/TEM), X-ray photoelectron spectroscopy (XPS), thermogravimetric analysis (TGA) and temperature programmed reduction with H 2 (H 2-TPR), as well as catalytic tests of WGS reaction showed that the synthesis method had significant impact on composition, morphology, structural properties and catalytic performance of obtained hybrid materials. The catalysts obtained by co-precipitation of metal oxides (NiO and/or CeZrO 2) on CNT walls demonstrated better dispersion of active phase and smaller particle size than catalyst obtained by depositing of powder CeZrO 2 or Ni-CeZrO 2. Moreover, the catalyst obtained by co-precipitation revealed better performance in WGS reaction; however, some CH 4 formation was noticed over Ni-CeZrO 2 /CNT system. The role of CeZrO 2 in catalysts performance in WGS as well as the importance of good metal-oxide contact were confirmed.

ACS omega, Dec 4, 2017

The successful future of 2D materials, which are crucial for accelerating technology development ... more The successful future of 2D materials, which are crucial for accelerating technology development and societal requirements, depends on their efficient preparation in an economical and ecological way. Herein, we present a significant advance in the top-down exfoliation and dispersion method via an aqua colloid approach. We demonstrate that a broad family of natural oil-in-water emulsification agents with an elevated hydrophilic/lipophilic balance acts in the exfoliation of layered materials and the formation of their concentrated colloids. The concentration exceeds 45 g/L for exfoliated few-layered graphene sheets possessing a micrometer size. The exfoliation of carbon nanofibers provides one of the best known unsupported and Nundoped metal-free catalysts to date in the selective dehydrogenation of ethylbenzene to styrene. Other examples include aqua colloids of exfoliated/dispersed nitrides, carbides, or nanodiamonds.

Organometallics, Aug 27, 2004

ABSTRACT The reaction of the bulky aminophenol 2-(CH2NMe2)-4-Me-6-CPh3-C6H3OH (1) with Al(iBu)3 y... more ABSTRACT The reaction of the bulky aminophenol 2-(CH2NMe2)-4-Me-6-CPh3-C6H3OH (1) with Al(iBu)3 yields via isobutane elimination the formation of the diisobutyl Al complex {6-(CH2NMe2)-2-CPh3-4-Me-C6H2O}Al(iBu)2 (2) in high yield. Reaction of 2 with B(C6F5)3 in the presence of NMe2Ph affords, along with isobutene, the salt compound [{6-(CH2NMe2)-2-CPh3-4-Me-C6H2O}Al(iBu)(NMe2Ph)][HB(C6F5)3] (3), consisting of a four-coordinate Lewis acidic Al cation associated with the borohydride HB(C6F5)3-, whose solid-state structure was determined by X-ray crystallography. When complex 2 is reacted with B(C6F5)3 (1 and 0.05 equiv) in the presence of benzophenone and benzaldehyde, the quantitative conversion to the hydroalumination products 4 and 5, respectively, is observed. This B(C6F5)3-catalyzed hydroalumination reaction, via a B(C6F5)3-mediated hydride abstraction/transfer reaction, represents a new type of reactivity for Al alkyl cations and illustrates the higher reactivity of Al cation/HB(C6F5)3- salts versus the classical Al cation/MeB(C6F5)3- and B(C6F5)4- salts.

Powder Technology, Jul 1, 2016

Journal of materials chemistry. A, Materials for energy and sustainability, 2013

Journal of materials chemistry. A, Materials for energy and sustainability, 2014

International Journal of Biological Macromolecules, Jul 1, 2023

Acta Crystallographica Section C-crystal Structure Communications, Dec 11, 2004

In the title compound, [Fe(C5H5)(C12H19NO)]I, the ferrocene moiety has an eclipsed conformation, ... more In the title compound, [Fe(C5H5)(C12H19NO)]I, the ferrocene moiety has an eclipsed conformation, with mean Fe-C bond lengths of 2.031 (4) and 2.020 (6) A for the substituted and unsubstituted cyclopentadienyl rings. The pyrrolidinium heterocycle adopts an envelope conformation and has its 1- and 2-substituents in a relative trans disposition. Strong (+/-)-charge-assisted N-H...I and C-H...I hydrogen bonds are present. The crystal structure is also stabilized by weak C-H...O interactions.

Tetrahedron-asymmetry, Oct 1, 2003

Circular dichroism spectra of a series of planar chiral 2-substituted ferrocene carboxaldehydes a... more Circular dichroism spectra of a series of planar chiral 2-substituted ferrocene carboxaldehydes and 2-ferrocenyl-1,1dicyanoethylenes are reported. They show Cotton effects associated with intramolecular charge transfer transitions and are related to the absolute configuration of these compounds.

arXiv (Cornell University), Oct 14, 2022

Four series of PLA based composite films containing horizontally aligned few layer graphene (FLG)... more Four series of PLA based composite films containing horizontally aligned few layer graphene (FLG) flakes of high aspect ratio and adsorbed albumin are prepared. The mechanical and thermal properties vary with percentage, dispersion degree and size of FLG flakes. Great improvement up to 290 and 360% of tensile modulus and strength respectively was obtained for the composite containing high lateral size of FLG at 0.17% wt., and up to 60 and 80% for the composite with very well dispersed 0.02% wt. FLG. The composites of PLA and PEG-PLLA containing very well dispersed FLG flakes at 0.07 % wt. are ductile showing enhancement of elongation at break up to respectively 80 and 88%. Relatively high electrical conductivity, 5 x 10-3 S/cm, is measured for PLA film charged with 3% of FLG.